b 1. Field of the Invention
This invention relates to a switching apparatus for an electrical appliance, more particularly to a switching apparatus with improved conducting unit and button assembly for activating the electrical appliance.
2. Description of Related Art
This invention is an improvement of a conventional switching apparatus, as shown in FIG. 3, which is installed in an electrical appliance for interconnecting electrically a power source, such as a dry cell, and a lamp bulb 19. The power source and the lamp bulb 19 are disposed within the electrical appliance.
The electrical appliance has a circumferential shell 18 which defines a cavity 180 for receiving the switching apparatus, the power source, and the lamp bulb 19. The circumferential shell 18 has an opening 181 formed therethrough and communicated with the cavity 180.
The switching apparatus includes a generally cylindrically shaped body 13 (see FIG. 2) disposed in the cavity 180 of the circumferential shell 18 adjacent to the opening 181. The body 13 has an outer peripheral wall surface which is disposed against an inner wall surface of the circumferential shell 18.
Referring to FIG. 1, the switching apparatus further includes a button assembly 14, a lamp socket assembly 15, a sealing member 16, and a coupling ring 17. The body 13 has a first part 130 in the shape of a segmented cylinder and a second part 131 in the shape of a complementary segmented cylinder. The first and second parts 130, 131 have abutting surfaces which have sloping planes (T) that are inclined longitudinally relative to an axis of the body 13. The sloping planes (T) on the first and second parts 130, 131 of the body 13 have a conforming sloping relationship (see FIG. 2) so that the first and second parts 130, 131 of the body 13 sealingly engage each other. The first part 130 has a first end portion provided with a conducting protrusion 133 for contacting one of the output terminals of the power source, a second end portion provided with an axially extending annular flange 132, and a radial button retaining passage 1301 positioned between the first and second end portions and aligned with the opening 181 of the circumferential shell 18 (see FIG. 3). The annular flange 132 of the first part 130 has externally and internally threaded portions 1321, 1322.
The button assembly 14 includes a body 140 which has a threaded protrusion 1403, a slidable button 142 that is mounted on the body 140, and two connecting wires 1401, 1402. The threaded protrusion 1403 can pass through the entire length of the button retaining passage 1301 into the opening 181 of the circumferential shell 18 (see FIG. 3). The button assembly 14 further includes a ring 1411 which is positioned within the button retaining passage 1301 and which has an internally threaded portion 141 that engages the threaded protrusion 1403 so as to position the button assembly 14 on the first part 130 of the insulated body 13. The connecting wire 1402 is connected electrically to the conducting protrusion 133 of the first part 130.
The sealing member 16, as shown in FIG. 3, has an edge portion interposed between the outer wall surface of the first part 130 and the inner wall surface of the circumferential shell 18, and a dome-shaped central portion covering the opening 181 of the circumferential shell 18.
The coupling ring 17 has internally and externally threaded portions 170, 171 which are engaged respectively with the externally threaded portion 1321 of the annular flange 132 of the first part 130 and the inner wall surface of the circumferential shell 18 so as to position the first part 130 on the circumferential shell 18.
Referring again to FIGS. 1 and 3, the lamp socket assembly 15 includes a compression spring 150, an envelope 151, and a lamp socket 152. The lamp socket 152 is provided with a passage which can receive the lamp bulb 19 and the envelope 151 therein, and has a first end section formed with an internally threaded portion 1522 for engaging an externally threaded portion 191 of the lamp bulb 19, and a second end section formed with an externally threaded portion 1521 for engaging the internally threaded portion 1322 of the annular flange 132 of the first part 130 of the insulated body 13. The compression spring 150 is positioned within the envelope 151 and is capable of interconnecting electrically the contact of the lamp bulb 19 and the connecting wire 1401 of the button assembly 14 at two end portions thereof.
Even though the combination of all of the components of the switching apparatus can provide a water resistance effect thereto, it is quite difficult to assemble the different components of the switching apparatus together since most of the components thereof are threaded on their inner or outer surfaces. In addition, a lot difficulty is encountered during the manufacture of these components, thus resulting in a higher manufacturing cost.